Default Block Size for HP Unix 11

Question

I'm trying to restore data from a dlt4 tape in a SDLT320 drive from a Windows Win2k3 Legato server, but during the time of the backup our Legato server was a HP Unix 11 box. I need to change the block size to make this happen. Anyone out there know what the default block size for HP Unix 11? Thanks in advance for your time.

ble1 · Accepted Answer

It doesn't just depend on OS. You can change it in NW, it can be changed by OS, by HBA, etc. Traditionally UNIX always had bigger block size than Windows and it might be if you have SP1 that OS is actually blocking you.

By default NW will use for dlt4 block size of 128KB (if media type was set so in original configuration).

mcprazak · Answer

Hrvoje, 128KB was the number I was looking for. Thank you very much for your help!

ble1 · Answer

You can use the scanner program to determine theallowed block size. Scanner won't show allowed block size, but rather the one used to write volume. That value might be set by NW, HBA or OS.

kamal.thakor · Answer

You can use the scanner program to determine the allowed block size. Enter the following command at the prompt:

# scanner -v device_name

where device_name is the name of the device as defined for the server. The block size is included in the following output from this command:

scanner: volume id 2641870849 record size 98304

The record size entry is the block size of the device, in bytes.

To solve problems with block size compatibility:
¿ For UNIX, you can change the block size by setting the following environment variable to the greatest common value for both systems. For example:

setenv NSR_DEV_BLOCK_SIZE_MEDIA_TYPE value

where:
¿ MEDIA_TYPE is the backup device type available to the NetWorker server (also found in the Media Type attribute of the Device resource in the NetWorker Administrator program). Note that the syntax for MEDIA_TYPE is all uppercase, with underscores (_) replacing blank spaces. Therefore, a device displayed in the NetWorker software as ¿4mm 20gb¿ would be listed as follows: 4MM_20GB

¿ value must be a multiple of 32 KB, with a minimum value of 32 KB.

¿ On Microsoft Windows only, you can install a later model HBA or upgrade to drivers that can support up to 128 KB blocks for the previous UNIX example. Windows also accepts the same environment variable format for setting block size as listed for UNIX.

Note: You must restart the NetWorker server for the environment variables to take effect.

NetWorker

Default Block Size for HP Unix 11

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